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    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>比较运算符</title>
    <script>
        console.log('11' < '5'); //true  既然是字符串了，当然是ascll值进行比较了
        console.log('abcd' > 0); //false
        console.log('abcd' > 1); //false
        console.log(3 >= 5); //false
        console.log(5 >= 4); //true
        console.log('4' >= 5); //false
        console.log('4' >= 2); // true
        console.log(true >= 0); //true
        console.log(null >= 0); //true
        console.log(undefined >= 0); //false
        console.log(null >= 1); //false
        //1.我们程序里面的等于符号是 ==  默认转换数据类型 会把字符串型的数据转换为数字型 （只要求值等）
        console.log(3 == 5); //false
        console.log('pink老师' == '刘德华'); //false
        console.log(18 == '18'); //true
        console.log('1' == 1); //true
        console.log(19 != '19'); //false
        //2.程序里有全等  ===   !==  (要求数据类型和值都相等)
        console.log(19 === 19); //true
        console.log(19 === '19'); //false
        console.log(19 !== '19'); //true
    </script>
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